B850 Pro A Unstable Post Issues
Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=97496
Printed Date: 19 Oct 2025 at 7:17am
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: B850 Pro A Unstable Post Issues
Posted By: skippyjbird
Subject: B850 Pro A Unstable Post Issues
Date Posted: 14 Feb 2025 at 12:30pm
I'm having terrible issues with a new Asrock B850 Pro A motherboard. The system has a Ryzen 9900X CPU and two kits of Corsair 64GB CMH64GX5M2B5200Z40K ver 3.43.01 RAM which is on the QVL list. Even stripping it down to just one of the 64GB kits, it will only post 20% of the time. The other times the status LEDs will roll through and get down to the boot LED being green and it will just hang there with the green boot led but not posted, no video output, no caps lock response. I've cycled through the different kits to rule out a bad stick of RAM and tried stripping it down to a single stick. It will sometimes post in any of these configurations but not with any regularity. When it does post it goes through the status lights gets to green boot light for a second, then the light flicks to white before all the status lights going off and it's posted.
I'm currently running the latest BIOS (3.18.AS02 [Beta]) but had the same issue with the previous 3.15 BIOS. I've tried leaving all memory settings on AUTO, enabling the EXPO 1 profile, and manually setting speed to 4800 with memory context restore off and quick boot off. Nothing seems to make any significant difference. RAM sticks are in the correct 2, 4 slot configuration when 2 sticks are installed.
Thinking I had a bad motherboard I ordered another and I'm experiencing the exact same issue with this board.
Very frustrating. Can someone offer some suggestions on how I can get some stability out of this system?
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Replies:
Posted By: eccential
Date Posted: 15 Feb 2025 at 4:03am
Can't think of much.
How are you installing the DIMMs? They take quite a lot of force to seat. So much so, I wouldn't install them with motherboard installed in a case. I'd only install it with motherboard on a well supported surface, like on top of the original motherboard shipping box with anti-static bag between them.
Open the latch on one side, slide in the DIMM in correct orientation, and push down from both sides. It should click in at both sides with audible thunk each time.
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Posted By: Saguiguilid
Date Posted: 28 May 2025 at 11:57pm
Has this issue been resolved? I'm experiencing the same frustrating problem.
Mine is a fresh build with a Ryzen 7 9800X3D, ASRock B850M Pro A, and an XPG 6000MHz CL30 (16x2) kit. The system often hangs with a solid green boot LED and no video output. After 3?? reboots, it might finally post. This has been happening consistently for the past 3 months, but now it won?™t boot at all?”just a solid green LED and no access to BIOS.
I?™ve tried:
Running a single RAM stick in every channel
Resetting the BIOS
Flashing to both the latest BIOS and the original release version
Unfortunately, nothing has worked. I?™m now considering replacing either the RAM or the motherboard, but I?™d really like to know if anyone has found a solution before going that route.
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Posted By: kinsher
Date Posted: 01 Jun 2025 at 1:46am
I have the exact same problem since updating to 3.25.
Asrock B850 Pro RS. Ryzen 9800x3D.
From a cold boot the system stays with the yellow-green light on. No display output, no caps lock. If I press the reset button the system then boots as normal. It happens every time the system is turned on from a power-off state.
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Posted By: Saguiguilid
Date Posted: 01 Jun 2025 at 2:42am
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I am now wondering if these events was caused by Asrock board frying Ryzen 9000 cpus.I ordered new mobo Asus prime b850m and cpu ryzen 8600g to further narrow it down. I'll keep you guys posted when these arrived.
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Posted By: lewin
Date Posted: 02 Jun 2025 at 7:43pm
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I'm having the same issue at the moment, no POST with a green status LED using a B850 LiveMixer and a 9600X. Did you guys have any luck solving the issue? Any updates?
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Posted By: kinsher
Date Posted: 04 Jun 2025 at 2:23am
No resolution for me at the moment. I contacted Asrock support and they suggested resetting the BIOS to factory defaults, but this did not solve the issue. They said they would contact HQ.
The only work-around for me is to press the reset button once it gets hung on the green light, then it boots normally.
My system is a new build and only ran on 3.20 for a few weeks so I don't think there has been any damage to the CPU.
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Posted By: kinsher
Date Posted: 06 Jun 2025 at 8:41am
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The only work around I have at the moment is to press the reset button on my case after it is stuck on the green light, then it boots normally.
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Posted By: Olsentw
Date Posted: 17 Jun 2025 at 4:21am
I have the same problem with Ryzen 7 9800x3d
Asrock b850 pro rs
Stock on green normalt i can just tap restart and it works now its full stock not even showing bios
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Posted By: cameron
Date Posted: 17 Sep 2025 at 6:14am
If the red and yellow lights come on and stay on, do the following:
1. leave it on
2. drive to starbucks
3. order a coffee
4. wait for the coffee
5. sit down and drink the coffee while watching every video on tiktok
6. drive back home
7. check to see if the red and yellow lights are still on
I've done a few ASRock builds lately, and the first time they power up, they go through some sheep counting exercise that takes forever. Memory testing and whatnot. It may take 5 minutes or more to finish. Just ignore it for a while and see if it actually finishes.
Every single time I do one of these builds, and hit the same exact annoying problem, I wonder if I did something wrong and I reseat the CPU etc. and then it dawns on me that probably nothing is wrong and it's just this stupid first-flight test it always does.
After one successful boot, this usually won't happen again until you change some hardware.
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Posted By: JustRick
Date Posted: 11 Oct 2025 at 3:58am
Hi Cameron.
I'm since about 3 weeks been experiencing the same issue as described by others (owned this system since january).
It is in fact not hanging at the memory training, as it goes past the blinking DRAM light, but gets stuck once it's at the green BOOT status light.
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Posted By: JustRick
Date Posted: 12 Oct 2025 at 5:42pm
Hi all! I found the culprit for me!
I made a post about it on Reddit for those interested. For me it was a bug where values of Competitive/Aggressive DRAM Profiles weren't properly reverted when switching back to AMD AGESA Default profile:
https://www.reddit.com/r/ASRock/comments/1o47ent/fix_for_asrock_stuck_green_boot_light_issue_after/" rel="nofollow - https://www.reddit.com/r/ASRock/comments/1o47ent/fix_for_asrock_stuck_green_boot_light_issue_after/
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